The present invention relates to a device for driving surgical instruments. In particular, it relates to a device of the type which can be used for driving rotating transluminal catheters, such as those which are capable of differential cutting.
Impairment of blood circulation caused by deposits of atherosclerotic plaque on the inner walls of arteries is a major cause of artery disease. Vaso-restrictions resulting in loss of adequate circulation can lead to coronary infarction (heart attack), impairment of peripheral organ function, loss of limbs, and other ills. Procedures, such as surgical bypass, endarterectomy, and balloon angioplasty, have been used in recent times to regain patency. Both bypass and endarterectomy are invasive techniques that are not always successful. Balloon angioplasty has been used with success, but patient selection criteria are restrictive. Also, balloon angioplasty, while the least invasive method, does not remove the obstruction. It simply pushes it aside.
Due to each method's respective deficiencies, a less invasive technique to remove plaque deposits is needed. One such method is described in U.S. Pat. No. 4,445,509 entitled METHOD AND APPARATUS FOR REMOVAL OF ENCLOSED ABNORMAL DEPOSITS which issued on May 1, 1984 to David C. Auth. The method involves the removal of plaque by cutting it away from the arterial wall using a differential cutting apparatus. This method allows for the removal of plaque without significant damage to the endothelial lining of a vessel and is applicable to catheter techniques.
Differential cutting is a process in which a difference in hardness of materials is exploited. If a relatively hard material exists over a softer substrate, then it is possible to cut the harder material away with a fluted edge cutter of appropriate velocity and frequency without cutting the substrate. The cutting edge pushes the softer material aside, but the harder material, not being as pliable, is cut before it can move away.
A spinning burr of appropriate design is advanced to the lesion by conventional percutaneous cut-down procedures. Vascular access via well known catheter techniques are used to advance a guide wire of appropriate design through the lesion. Then, a drive catheter with a differential cutting head is advanced to the lesion within a guide sheath. The guide sheath is used to protect the endothelial lining from unnecessary abuse and to stabilize the drive catheter.